Today it was announced by the USB-IF (USB Implementers Forum) that the latest USB connector which we first caught a glimpse of in April has been finalized, and with this specification many of the issues with USB as a connector should be corrected. USB, or Universal Serial Bus, has been with us for a long time now, with the standard first being adopted in 1996. At the time, it seemed very fast at up to 12 Mbps, and the connector form factor was not an issue on the large desktop PCs of the day, but over the years, the specifications for USB have been updated several times, and the connectors have also been updated to fit new form factor devices.

In the early ‘90s, when USB was first being developed, the designers had no idea just how universal it would become. The first connectors, USB-A and USB-B, were not only massive in size, but the connection itself was only ever intended to provide power at a low draw of 100 mA. As USB evolved, those limitations were some of the first to go.

First, the mini connectors were introduced, which, at approximately 3 mm x 7 mm, were significantly smaller than the original connector, but other than the smaller size they didn’t correct every issue with the initial connectors. For instance, they still had a connector which had to be oriented a certain way in order to be plugged in. As some people know, it can take several tries to get a USB cable to connect, and has resulted in more than a few jokes being made about it. The smaller size did allow USB to be used on a much different class of device than the original connector, with widespread adoption of the mini connectors on everything from digital cameras to Harmony remotes to PDAs of the day.

In January 2007, the Micro-USB connector was announced by the USB-IF, and with this change, USB now had the opportunity to become ubiquitous on smartphones and other such devices. Not only was the connector smaller and thinner, but the maximum charging rate was increased to up to 1.8 A for pins 1 and 5. The connection is also rated for at least 10,000 connect-disconnect cycles, which is much higher than the original USB specification of 1,500 cycles, and 5,000 for the Mini specification. However once again, the Micro-USB connector did not solve every issue with USB as a connector. Again, the cable was not reversible, so the cable must be oriented in the proper direction prior to insertion, and with USB 3.0 being standardized in 2008, the Micro connector could not support USB 3.0 speeds, and therefore a USB 3.0 Micro-B connector was created. While just as thin as the standard connector, it adds an additional five pins beside the standard pins making it a very wide connection.

With that history behind us, we can take a look at the changes which were finalized for the latest connector type. There are a lot of changes coming, with some excellent enhancements:

Completely new design but with backwards compatibility

Similar to the size of USB 2.0 Micro-B (standard Smartphone charging cable)

Slim enough for mobile devices, but robust enough for laptops and tablets

Reversible plug orientation for ease of connection

Scalable power charging with connectors being able to supply up to 5 A and cables supporting 3 A for up to 100 watts of power

Designed for future USB performance requirements

Certified for USB 3.1 data rates (10 Gbps)

Receptacle opening: ~8.4 mm x ~2.6 mm

Durability of 10,000 connect-disconnect cycles

Improved EMI and RFI mitigation features

With this new design, existing devices won’t be able to mate using the new cables, so for that reason the USB-IF has defined passive cables which will allow older devices to connect to the new connector, or newer devices to connect to the older connectors for backwards compatibility. With the ubiquity of USB, this is clearly important.

There will be a lot of use cases for the new connector, which should only help cement USB as an ongoing standard. 10 Gbps transfer rates should help ensure that the transfer is not bottlenecked by USB, and with the high current draw being specified by connectors, USB may now replace the charging ports on many laptops as well as some tablets that use it now. The feature that will be most helpful to all users though is the reversible plug, which will finally do away with the somewhat annoying connection that has to be done today.

As this is a standard that is just now finalized, it will be some time before we see it in production devcies, but with the universal nature of USB, you can expect it to be very prevalent in upcoming technology in the near future.

Post Your Comment

66 Comments

You can't compare USB with Thunderbolt, because the underlying idea of both is totally different! This makes Thunderbolt much more versatile, but also more expensive. Not because of the high transfer speeds, but because of the protocol.There's no reason to complain about too fast transfer speeds. Maybe you don't have a use yet, but in 2 or 3 years for sure. Be happy that you don't need a new USB connector then, again.Show me (don't just assume) why the step-up to 10 GB/s makes it more expensive.And no, faster speeds don't appear magically, they become possible thanks to a lot of research and improvements in multiple areas. But this doen't mean, the hardware becomes more expensive. Sometimes it's just better algorithms, error corrections, optimized protocols which allow huge speed improvements. Not always is a hardware change necessary.Reply

Here's an analogy: you can make really awesome rockets and make better designs every year for a century but it will still always be hard to leave earth's atmosphere. Switching a 1m copper cable at 10 Gbps is the exact same thing. We've been able to do it for a while but it's not on your phone for a reason. It's the same reason you have 100-base-t routers and at best 1000-base-t in your home and not fibre. We all want more speed and would use it if we had it but I'd like my however many billion usb devices to stay cheap.Reply

Seconded.They designed the *connector* to accept and work at the fastest usb 3.1 speed which is 10Gbps.The price difference for that is negligeable if any. It is just good design for your plug to support your highest standard.Usb cables are dumb. They are just copper wires with passive plugs. Cost will be low.Reply

If Type-C cables must support 10Gbps and 3A, they will guaranteed be more expensive than 5Gbps and 1A. As for how much...probably less than a buck in manufacturing, but companies will probably charge a much higher premium.Reply

The funny thing about standards is that they usually become standard well after the technology is proven. I don't imagine the USB-IF said "You know what be awesome?" and then magic'd up a sweet idea for super fast connectivity that's also universal.

It's using the USB 3.1 standard, which was announced last year. USB 3.0 was announced in 2008, carried a premium and still has not completely displaced USB 2.0. The main difference here is that USB-C is designed for compatibilty with mobile and desktop applications, in both size and utility, so unlike the shift to USB 3.0, which simply stratified the market, manufacturers can actually save money by switching to USB-C. OEMs like Samsung and Apple, whose products span multiple categories only have to purchase a single connector type in large quantities for all of their products vs. smaller quantities of USB-A, USB-B, USB-B micro, etc... and support a single protocol on future products.

Adoption will likely occur first on mobile applications, where peripherals are less of a concern. Desktops and laptops will still support USB-B for a number of years to come, but as with all new technologies, halo products will see it first and it will trickle down to the mainstream products. I wouldn't be too concerned with the premium associated, early adopters always pay premiums and the rest of us that buy our products well after the technology is mature just chalk up the price to inflation.Reply